Dynamos in Stellar Convection Zones: of Wreaths and Cycles

Abstract

We live near a magnetic star whose cycles of activity are driven by dynamo action beneath the surface. In the solar convection zone, rotation couples with plasma motions to build highly organized magnetic fields that erupt at the surface and undergo relatively regular cycles of polarity reversal. Despite our proximity to the Sun, the nature of its dynamo remains elusive, but observations of other solar-type stars show that surface magnetism is a nearly ubiquitous feature. In recent time, numerical simulations of convection and dynamo action have taken tremendous strides forward. Global-scale organization and cyclic magnetism are being achieved by several groups in distinctly different solar and stellar simulations. Here I will talk about advances on the numerical front including wreath-building dynamos which may occupy stellar convection zones. I will discuss the interplay between the new simulations, various classes of mean-field models, and current and upcoming solar and stellar observations.

10 pages, 5 figures, a4 format; proceedings for SOHO 24/GONG 2010 conference: "A new era of seismology of the Sun and solar-like stars," Aix-en-Provence, France, June 27-July 4, 2010 (JPCS)

References in corpus (6)

• Global-Scale Turbulent Convection and Magnetic Dynamo Action in the Solar Envelope
• Solar differential rotation and meridional flow: The role of a subadiabatic tachocline for the Taylor-Proudman balance
• Structure and Evolution of Giant Cells in Global Models of Solar Convection
• Exploring the Physical Basis of Solar Cycle Predictions: Flux Transport Dynamics and Persistence of Memory in Advection versus Diffusion Dominated Solar Convection Zones
• Rapidly Rotating Suns and Active Nests of Convection
• Convective dynamos in spherical wedge geometry

Cited by in corpus (2)

• Buoyant Magnetic Loops in a Global Dynamo Simulation of a Young Sun
• Entropy Rain: Dilution and Compression of Thermals in Stratified Domains